1. Field of the Invention
The present invention relates to a coil inserter for inserting a stator coil into a slot of a stator iron core in an electric motor.
2. Description of the Prior Art
With reference to a schematic diagram of FIG. 4, the description will be made of an example of a conventional coil inserter 100.
On an inserter tool 101, a plurality of blades 102 are vertically installed on one circumference at predetermined intervals so as to correspond to teeth between slots of a stator iron core 200. At the upper ends of these blades 102 upwardly extending from the inserter tool 101, there is inserted an alignment tool 103 for guiding the blades 102 onto an inner peripheral surface of the stator iron core 200.
Also, in a space inside the plurality of blades 102 vertically installed on one circumference, there is arranged a stripper 104, which is moved in an up-and-down direction relative to the blades 102 by driving a shaft 106 by a driving source 105.
Further, on the outer periphery of the plurality of blades 102 vertically installed, a plurality of wedge guides 107 are vertically installed on a wedge guide holder 108 on the circumference at predetermined intervals. These wedge guides 107 hold, on the outer side thereof, wedges 110 configured by insulating paper or the like. The wedge guides 107 move in an up-and-down direction relative to the blades 102 by driving a wedge pusher 109.
After a stator winding (coil 300), to be mounted into the slots of the stator iron core, is inserted between the blades 102, the alignment tool 103 is fittingly coupled with the blades 102 at their upper ends, and the alignment tool 103 is inserted into an inner surface of the stator iron core 200 (state of FIG. 4).
Then, the stator iron core 200 is caused to move, while being guided by the alignment tool 103, relative to the coil inserter 100 until upper ends of the wedge guides 107 come into contact with end portions of the slots of the stator iron core 200.
Thereafter, the driving source 105 is driven to move the stripper 104 upward. Then, the coil 300 is pushed up by the stripper 104 to be inserted into the slots of the stator iron core 200. Further, the driving source 105 drives to push up the wedge pusher 109 to thereby raise a wedge guide holder 108 and the wedge guides 107. Then, the wedge 110 held by the wedge guides 107 is inserted into the slots. As a result, this wedge 110 covers a slot opening into which the coil 300 has been inserted.
The stripper 104 rises beyond a position of the upper end surface of the stator iron core 200 at the upper end surface position, whereby the coil 300 will be completely inserted into the slots of the stator iron core 200. The wedge guide 107 rises until it reaches the upper end surface position of the stator iron core 200, whereby the wedge 110 will cover the slot opening over its entire area.
Thereafter, the driving of the driving source 105 is stopped to remove the alignment tool 103. The stator iron core 200 is caused to move upward to thereby extract the stator iron core 200 from this coil inserter 100. At this time, the blade 102 and the wedge guide 107 retract from the stator iron core 200, but the coil 300 and the wedge 110 are prevented from moving by friction or the like, and are held within the slots of the stator iron core 200.
In the above described conventional coil inserter 100, the coil 300 between the blades 102 is directly pushed up toward the stator iron core 200 by the movement of the stripper 104 to be inserted into the slots of the stator iron core 200. At this time, the coil 300 may be crushed by a pushing-up force of the stripper 104 to be stuffed up between the blades 102, that is, a locking phenomenon may occur. There may also arise the inconvenience that the coil 300 is damaged by the blade 102 when the coil 300 is transferred by the movement of the stripper 104.
Therefore, in order to restrain this locking phenomenon or the like from occurring, it is necessary to pay attention to selection of the diameter of coil stock and setting of a coil filling factor into the slots.
In order to completely insert the coil 300 into the slots of the stator iron core 200, the length of the blade 102 has to be equal to or more than the length of the stator iron core 200 in a vertical direction, as the coil 300 is pushed by the stripper 104 and guided by the blades 102. The reason is as follows. That is, at a position where the upper end of the wedge guide 107 comes into contact with the end portions of the slots of the stator iron core 200, the movement of the stator iron core 200 relative to the coil inserter 100 is caused to stop. Then, the stripper 104 is caused to move for starting to insert the coil 300 into the slots. If the blades 102 has not yet reached the upper end portion of the stator iron core 200 in that state, the coil 300 cannot be completely inserted into the slots even if the stripper 104 is caused to move up to such a position as to go beyond the upper end surface of the stator iron core 200.
In this respect, Japanese Patent Application Laid-Open No. 54-126905 disclosed a coil inserter in which the length of the blades is made shorter.
Further, since the conventional coil inserter 100 requires a pushing-up mechanism such as the wedge pusher 109, there is the problem that an apparatus as the coil inserter 100 becomes longer in a vertical direction and it is difficult to save the space.
It is an object of the present invention to improve the above described conventional problems, and to provide a coil inserter capable of avoiding any locking phenomenon and further to provide a coil inserter capable of miniaturizing in a simple mechanism.
In a coil inserter according to the present invention, one end of the plurality of blades for guiding the coil into the slots of the stator iron core is coupled and fixed to a blade holder for supporting, and the stripper for supporting the coil is disposed on the inner periphery side of the blade. This stripper is fixed to a base for supporting the entire inserter. Thus, the stator iron core is urged in the axial direction of the electric motor using stator iron core inserting means, and the blades are inserted between the slots of the stator iron core, whereby the coil supported by the stripper is adapted to be inserted into the slots of the stator iron core.
Particularly, the blade holder is made freely advanceable and retractable. Also, there is provided a wedge guide for holding both ends of the wedge and supporting the rear surface of the wedge in the longitudinal direction, and both ends of the wedge guide are coupled and fixed to the stripper and the base respectively.
By using the above described coil inserter, the stator iron core is caused to advance or retract relative to the coil inserter, whereby the coil is inserted into the slots of the stator iron core. Also, the stator iron core is caused to advance or retract relative to the coil inserter, whereby insertion of the coil into the slots is started, and the blade holder is caused not to advance or retract until the coil reaches a predetermined position of the stator iron core, while after the coil reaches the predetermined position, the blade holder is also caused to advance or retract in response to the advancement or retraction of the stator iron core for inserting the coil. Thus, the locking phenomenon is prevented from occurring. Also, the stator iron core is caused to advance or retract relative to the coil inserter, whereby the wedge is inserted into the slots without being pushed up.
According to the present invention, a small-sized coil inserter can be obtained in a simple mechanism, without causing any locking phenomenon. Since the coil inserter is capable of preventing the locking phenomenon from occurring, it is capable of freely selecting a diameter of material for coil, and improving a filling factor for the coil 3 into the slots of the stator iron core. Also, it can be miniaturized in a simple mechanism and its full length (height) can be made low. Therefore, a space-saving coil inserter can be provided at low cost.